Jovian Magnetosphere-Satellite Interactions: Aspects of Energetic Charged Particle Loss (Paper 8R1321)
Jovian Magnetosphere-Satellite Interactions: Aspects of Energetic Charged Particle Loss (Paper 8R1321)
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木星磁层-卫星相互作用：高能带电粒子损失的各个方面（论文 8R1321）
DOI：
10.1029/rg017i003p00369
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发表时间：
1979
影响因子：
--
通讯作者：
M. Thomsen
中科院分区：
文献类型：
--
作者：
M. Thomsen
高能带电粒子的观测获得的先驱者10和11附近的内木星卫星的轨道进行审查，特别强调这些意见的影响方面的可能模型的带电粒子的访问卫星表面。粒子的俯仰角分布和所观察到的能量依赖的强度耗尽在卫星轨道上观察到的影响进行比较与预测的卫星sweepup几种不同的访问模型的基础上。妨碍比较的两个主要不确定性是与卫星电导率和电离层发电机电场功率谱有关的不确定性。卫星电导率很重要，因为它控制着粒子进入卫星表面，从而控制着寿命τ;发电机功率谱很重要，因为它控制着径向扩散系数的大小和能量依赖性。尽管存在这些不确定性，我们仍然可以得出以下结论。(1)在木卫一轨道上的电子俯仰角分布与基于扫描的预期是兼容的。(2)在所有三个内部卫星上观测到的电子耗尽的能量依赖性（Amalthea，Io和Europa）与基于卫星及其通量管的完美导体模型的预期不相容，但与完美绝缘或部分传导卫星的预期能量依赖性相容;在这三颗卫星上，质子损失的能量依赖性似乎也与绝缘或部分导电卫星的吸收相一致，但只有在发电机功率的某些形式光谱是假设的。(3)然而，观察到在木卫一的质子损失比电子损失强得多，与基于扫描的预期相矛盾。(4)最有吸引力的解释是，在木卫一的质子-电子的差异是，在木卫一的轨道上的大质子损失主要是由于增强的俯仰角散射在该地区的等离子体密度较高，可能更大的湍流与卫星，而不是卫星扫描单独。
Observations of energetic charged particles obtained by Pioneers 10 and 11 near the orbits of the inner Jovian satellites are reviewed with particular emphasis on the implications of these observations with regard to possible models of the access of charged particles to the satellite surfaces. The observed effects on particle pitch angle distributions and the observed energy dependence of the intensity depletions seen at the satellite orbits are compared with predictions of satellite sweepup based on several different access models. The two major uncertainties which hamper the comparisons are those associated with the satellite conductivities and the ionospheric dynamo electric field power spectrum. The satellite conductivity is important because it governs the access of the particles to the satellite surface and therefore the lifetime τ; the dynamo power spectrum is important because it controls the magnitude and energy dependence of the radial diffusion coefficient. In spite of these uncertainties we can nevertheless make the following conclusions. (1) The electron pitch angle distributions at Io's orbit are compatible with expectations based on sweeping. (2) The energy dependences of the observed electron depletions at all three inner satellites (Amalthea, Io, and Europa) are incompatible with expectations based on a perfect conductor model of a satellite and its flux tube but are compatible with the energy dependence expected for perfectly insulating or partially conducting satellites; the energy dependences of the proton losses at all three satellites also appear to be compatible with absorption by an insulating or partially conducting satellite but only if certain forms of the dynamo power spectrum are assumed. (3) However, the proton losses at Io are observed to be much stronger than the electron losses, in contradiction to expectations based on sweeping. (4) The most attractive explanation for the proton-electron discrepancy at Io is that the large proton losses at Io's orbit are principally due to enhanced pitch angle scattering in the region of higher plasma density and probably greater turbulence associated with the satellite rather than to satellite sweeping alone.